1. Field of the Invention
The present invention relates to a capacitative element which utilizes a wiring formed on a substrate as electrodes.
2. Description of the Related Art
In a semiconductor integrated circuit, a capacitative element which utilizes a wiring formed on a semiconductor substrate as electrodes is devised in various ways. For example, a capacitative element disclosed in Japanese Patent Laid-Open No. Sho 64-084616 (hereinafter referred to as Patent Document 1) has a structure that a first electrode and a second electrode are formed in sinking comb-like shapes, respectively, and layers having the respective sinking comb-like portions, of the first electrodes, engaged with each other through a dielectric are laminated. In this capacitative element, an electrode structure is reversed in such a way that the first electrode and the second electrode face each other in the upper and lower layers.
In addition, Japanese Patent Laid-Open No. 2000-252428 (hereinafter referred to as Patent Document 2) discloses a capacitative element structured in such a way that a first electrode and a second electrode are alternately disposed in a first level, the first electrode and the second electrode are alternatively disposed in a second level so as to cross the first electrode and the second electrode in the first level, and this pattern is repetitively formed. In this case, the first electrodes in the first and the second level, and the second electrodes in the first and second levels are connected to each other through via holes, respectively.
In addition, U.S. Pat. No. 6,690,570 (hereinafter referred to as Patent Document 3) discloses a capacitative element structured in such a way that in each of first and second levels, a first electrode and a second electrode are alternately disposed in the same direction, and in each of the third and fourth levels, the first electrode and the second electrode are alternately disposed in the same direction perpendicularly intersecting with the direction of disposition of the first electrode and the second electrode in each of the first and second levels. In this case, the first electrodes in the first to fourth levels, and the second electrodes in the first to fourth levels are connected to one another through via hoes, respectively.
Also, Japanese Patent Application No. 2005-108874 (hereinafter referred to as Patent Document 4) discloses a capacitative element having such a function that the other electrode is shielded by one electrode. In this capacitative element, a first electrode having a sinking comb-like shape, and a second electrode having another sinking comb-like shape are engaged with each other through a dielectric in a first level, and the first electrode having the sinking comb-like shape is surrounded on outer three sides by the second electrode having another sinking comb-like shape.
Any of the capacitative elements described above has such a structure that a capacitance per unit area is sufficiently obtained while a wiring is utilized.